The Flow Cytometry Shared Service of the Arizona Cancer Center provides cell sorting and enhanced cytofluoragraphic analysis in support of research at the Arizona Cancer Center. This facility is the only one within the University of Arizona College of Medicine providing analysis and sterile sorting of un-fixed, human cells. In addition, the Shared Service technologist and service director provide consultation to Cancer Center investigators in design and interpretation of flow cytometry and cell sorting studies. Developmental studies are conducted for new Cancer Center investigators and to allow established investigators to enter new and interactive fields of investigation. Recent instrument and software acquisitions have greatly expanded available services and capabilities of this facility.